TY - JOUR
T1 - A jet-driven, extreme high-velocity outflow powered by a cold, low-luminosity protostar near NGC 2023
AU - Sandell, G.
AU - Avery, L. W.
AU - Baas, F.
AU - Coulson, I.
AU - Dent, W. R.F.
AU - Friberg, P.
AU - Gear, W. P.K.
AU - Greaves, J.
AU - Holland, W.
AU - Jenness, T.
AU - Jewell, P.
AU - Lightfoot, J.
AU - Matthews, H. E.
AU - Moriarty-Schieven, G.
AU - Prestage, R.
AU - Robson, E. I.
AU - Stevens, J.
AU - Tilanus, R. P.J.
AU - Watt, G. D.
PY - 1999/7/1
Y1 - 1999/7/1
N2 - We have discovered an extreme high-velocity bipolar CO outflow in the vicinity of NGC 2023, with total outflow velocities of ∼200 km s-1. At very high velocities this outflow is jetlike with an opening angle ≤4°, while it shows a separate outflow lobe at low velocities. The outflow is bipolar and exhibits a clear mirror symmetry, which suggests that the source powering the outflow is episodic or precessing. The dynamical timescales for the outflow are ≤3000 yr. We identify the source driving the CO jet with a deeply embedded low-luminosity submillimeter double source (separation ∼23″), where the primary component lies on the symmetry axis of the outflow and has all the signatures of a "class 0" protostellar object. Analysis of molecular data and (sub)millimeter photometry suggests that the driving source is cold and compact, with a luminosity of ≲10 L⊙ and a total mass of 1.8-4.6 M⊙. It has no near-IR counterpart, it drives an extremely young outflow, and it emits a large fraction of its luminosity in the submillimeter regime. Both millimeter sources have low dust emissivity, β ∼ 0.8-1.3, similar to what is found for other class 0 objects, while the surrounding molecular cloud core appears to have a β ∼ 2.0, the canonical value for "normal" interstellar dust in the submillimeter regime.
AB - We have discovered an extreme high-velocity bipolar CO outflow in the vicinity of NGC 2023, with total outflow velocities of ∼200 km s-1. At very high velocities this outflow is jetlike with an opening angle ≤4°, while it shows a separate outflow lobe at low velocities. The outflow is bipolar and exhibits a clear mirror symmetry, which suggests that the source powering the outflow is episodic or precessing. The dynamical timescales for the outflow are ≤3000 yr. We identify the source driving the CO jet with a deeply embedded low-luminosity submillimeter double source (separation ∼23″), where the primary component lies on the symmetry axis of the outflow and has all the signatures of a "class 0" protostellar object. Analysis of molecular data and (sub)millimeter photometry suggests that the driving source is cold and compact, with a luminosity of ≲10 L⊙ and a total mass of 1.8-4.6 M⊙. It has no near-IR counterpart, it drives an extremely young outflow, and it emits a large fraction of its luminosity in the submillimeter regime. Both millimeter sources have low dust emissivity, β ∼ 0.8-1.3, similar to what is found for other class 0 objects, while the surrounding molecular cloud core appears to have a β ∼ 2.0, the canonical value for "normal" interstellar dust in the submillimeter regime.
KW - ISM: individual (NGC 2023)
KW - ISM: jets and outflows
KW - ISM: molecules
KW - Stars: pre-main-sequence
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U2 - 10.1086/307367
DO - 10.1086/307367
M3 - Article
AN - SCOPUS:0033159951
SN - 0004-637X
VL - 519
SP - 236
EP - 243
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1 PART 1
ER -